Electrical circuit controlling device



Mar 4, 1 F. F. HUMPHREYS ETAL 2,233,532

ELECTRICAL CIRCUIT CONTROLLING DEVICE Filed Sept. 1, 1937 IHSULAT\OH @M,My

Patented Mar. 4, 1941 PATENT OFFICE 2,233,532 ELECTRICAL CIRCUITCONTROLLING- DEVICE Ferdinand Humphreys,

Terjesen, Hoboken, N.

Caldwell, and Tellef A. J., assignors to Signal Engineering inManufacturing Company, New

York, N.

Application September 1,

Y., a corporation of Massachusetts 1937, Serial No. 161,956

5 Claims. (Cl. 200-87) The present invention relates to electricalcircuit controlling devices, of the type commonly known as relays, andhas for its object to provide an improved device of this character thatis capable of ready adiustment to meet different operating conditions.

The above and other advantageous features of the invention willhereinafter more fully appear from the following description withreference to the accompany g drawing in which:

Fig. l is a view in front elevation of a circuit controlling deviceembodying the invention.

Fig. 2 is a view in side elevation of the parts shown in Fig. l. I

Fig. 3 is a fragmentary view partially in section illustrating themounting of the yoke for the back contacts.

Fig. 4 is a Fig. 3. a

Fig. 5 isb. fragmentary arm assembly. J

Figs. 6 and 7 are perspective views illustrating the contact arm andcontact structure separated from each other.

Fig. 8 is a fragmentary sectional view through one of the back contacts.

Fig. 9 is a perspective view of a back contact assembly. g

Like reference characters refer to like parts in the diflerent figures.

Referring first to Figs. l and 2, the invention is shown, for purposesof illustration, as being embodied in a circuit controller of the relaytype, the essential elements of which comprise an insulating base Icarrying U-shaped core I one end of which is surrounded by an energizingwinding 3. A magnetic armature 4 is pivotally supported on the lower endof the core leg and carries a pair of arms I suitably insulated from thearmature 4 at 6. Each arm I carries a pair of contacts I projecting fromopposite sides of an arm 5, which contacts I constitute an assemblyseparately removable from the-arm, as will'be hereinafter described.

In the normal deenergized condition of the winding 3 the armature 4occupies the position of izza with the arm contacts I in engagement witha pair of back contacts I mounted on a yoke t of insulating material.Thearmature 4 provides an extension II, and a spring ll cooperating withthis extension ll tends to pull the. armature 4 downwardly about itspivot and maintain the arm contacts I in engagement with predeterminedpre's- 1 plan view of the parts shown in view of one contact the backcontacts I with a cot curvature the same pivot sure dependent upon theadjustment of the spring ll.

Upon energization of the winding 3, the armature 4 will be turnedupwardly about its pivot to move the arm contacts I into engagement withthe pair of front stationary contacts I2 mounted on the base I. Arelayof the type described thus far is known as a front and back contactrelay, wherein the flow of current through the back contacts 8 ismaintained for one outside circuit condition as long as the winding 3remains deenergized, while flow of current between the frontcontacts I2is maintained for another circuit condition, as long as the winding 3 isenergized. The amount-of current required to energize the windingdepends upon the air gap between the armature 4 and the end of theopposed core leg, combined with the pull of the spring II and this airgap in turn depends upon the distance between the front and backcontacts l2 and 8, respectively. As previously pointed out, theinvention contemplates the provision of means whereby the relativeposition between the contacts l2 and 8 can be varied without disturbingthe parallel relation between the contact faces and with the assurancethat the contacts I carried by the arm 5 will always engage thesestationary contacts with a uniform pressure for different settings. Y

L To this end, the yoke 9 carrying the contacts 8 is mounted on a blockI: secured to the top 'of the core 2 by a screw l4. vides a curved uppersurface II and the yoke 9 provides a correspondingly curved slot It,with a rib Ilia located centrally of the surface l5 received in a groovelGa at the top of the slot I, see Fig. 4. As best shown in Fig. 3, thecenter of the block surface II and the yoke slot I6 is located at thecenter of the pivot ll of the armature 4. As a result of the abovedescribed mounting of the yoke 9', it follows that any movement of theyoke for the purpose of adjusting the position of the contacts 8 isaccomplished without disturbing the parallel relation between thefacesof the arm contacts 1 and the back contacts I. This is becausemovement of the contacts t with the yoke 9 is about I! on which thearmature 4 turns with thecontacts I. In order to secure the yoke 9 inadjusted position the block II provides a number of pairs of threadedhole! I. adapted to receive screws l9 passing througl: the slot It inthe yoke 9, or separate blocks It with diflerently drilled pairs ofholes It, can be used. In this way,

The block l3 pro-- the yoke 9 can be set in order to determine theinitial air gap between the armature I and the core leg.

In addition to the adjustment of the yoke I in order to obtain settingof the contacts I in unison, there is also provided means for adjustablymounting each contact I separately on the yoke. As best shown in Figs. 8and 9, each contact I is mounted on a threaded stud 20 received inanopening 2! extending through the yoke I. The stud II carries acircular nut 22 having an enlarged portion 23 of angular form which isreceived in a correspondingly shaped seat 24 adjacent the yoke opening2i, so that the nut and stud cannot turn in the opening II. The end ofthe stud Ill is received in an internally threaded sleeve II tumable inthe opening II and the sleeve II provides an enlarged head lI receivablein a seat 21 surrounding the opening 2|.

As best shown in Fig. 1, the head 20 provides openings "a for receivinga suitable tool, whereby the sleeve II may be turned in the opening 2|.Since the angular portion 23 of the nut 22 cannot turn in the opening2|, clockwise turning of the head N, as viewed in Fig. 1, causes thestud 20 to be clamped in the opening ll between the seats II and 21. Inthis way each contact I can be locked in position on the yoke I andminor adjustments of the contacts I with respect to the armcontacts 1can be made individually after an initial adjustment of the yoke I byshifting the nut 22 on any stud l! in order to obtain just the rightengagement between the opposed surfaces of the contacts 1 and I. Eachhead 2I also provides a threaded opening to receive a terminal screw 28for connecting a conductor to the contact I. Furthermore it is an easymatter to remove an individual contact I and replace it with a new onewithout in any way disturbing the setting of the other three contactscarried by the yoke I.

As previously pointed out, a pair of arm con-.

tacts l are constructed as a unit for mounting on an arm I and thisconstruction is best shown in Figs. 5, 6 and 'l. The contacts I areconnected by a cross bar 29 providing an opening through which freelyextends a pin II providing heads Illa at its ends. Washers II aremounted on the pin III on either side of the bar 2! and a coil spring I!surrounds the free portion of the at the pin II between its head Ila andeach washer Ii. Thus each washer Ii is yieldingly maintained inengagement with the bar I! so that normally in the assembled contactunit, the washers ll extend in parallel relation.

As best shown in il lg. 8, each arm I provides a slot It the sides ofwhich, are parallel near the base of the arm. The free end of the arm Iis enlarged as indicated at N and the slot 33 widens to provide curvedportions lI only slightly less in diameter than the contacts 1 andwashers II. When it is desired to position an assembled contact unit,such as shown in Fig, 'l, in an arm I, the extremities of the arm I areflexed, as indicated in dotted lines in Pig. 8, to permit the insertionof the contacts I between the opened sides of the slot portions II. Thisresults in the washers ll engaging opposite sides of the arm I and thesprings 82 tend to yieldlngly maintain the washers II in suchenlalement. Therefore the entire contact assembly is in effect floatingendofthearmlsothateachcontactfl may seekits own adjustment with thefront or back contact I! or. Obviously when the contacts I becomeworn.rtheentire assembly can bereadilyremovedfromanarm lbyflexingitaaeasaa so as to release the washers II and a new contact unitsubstituted, without in any way disturbing any other parts of the deviceor necessitating removal from its mounting, this latter feature beingclaimed in our copending divisional application, flied August 3, 1940,Serial No. 350,- 670.

As previously pointed out, the spring ll serves to yieldingly maintainthe contacts I in engagement with contacts I and the degree of contactpressure can be readily controlled by a convenient adjustment of thespring tension. For this purpose, one end of the spring II is anchoredby threading its end coils around a fixed screw 38. The opposite end ofthe spring ii is similarly engaged with threads on a stud I! extendingthrough an opening in the armature extension II. The stud 31 carries alock nut ll between the extension Ill and a guide SI, and an adjustingnut ll beyond the extension II. By turning the adjusting nut II in onedirection or the other, the tension of the spring ii can be increased ordec eased to control the contact pressure. Any setting of the spring llthus obtained can be maintained by turning the lock nut II up againstthe extension II to cause the end of the nut II to be received within anangular seat Ilia provided in the extension l0. Thus the lock nut IIwill effectively prevent any backing of! of the adjusting nut llfollowing an adjustment of the spring and which might otherwise occur asa result of repeated operations of the armature.

From the foregoing it is apparent that by the present invention there isprovided a circuit controlling device, or relay, of the front and backcontact type in which the air gap can be closely adjusted to the desiredpoint, without in any way effecting the proper engagement between thesurfaces of the contacts.

We claim:

1. A device of the class described, comprising in combination acoremember carrying an energizing winding, an armature pivotally mountedon said core member carrying a contact at its free end,. a yoke ofinsulating material mounted on said core member and providing a stopagainst which said armature contact rests when said winding isdeenergized, said yoke providing a curved surface along which it isadjustable to vary the position of said contact stop and therebydetermine the air gap between the free end of said armature and saidcore, with the center of curvature of said yoke surface locatedsubstantially at the pivotal axis of said armature.

- 2. A device of the class described, comprising in combination a coremember carrying an energizing winding, an armature pivotally mounted onsaid core member carrying a contact at its free end, a yoke ofinsulating material mounted on said core member and providing a stopagainst which said armature contact rests when said winding isdeenergized, a block mounted on said core providing a surface curvedabout the pivotal axis of said armature, with said yoke providing acorrespondingly curved surface, and means for securing said yoke andsaid block'together with said curved surfaces in different relativepositions, whereby to vary the position of said yoke stop and the lengthof the air gap between said armature and core. I p

.3. Adevice of the class described, comprising in combination a U-shapedmagnetic core having a winding carried by one leg thereof and anarmature pivotally mounted at the end of the other core leg, contactsextending upwardly from said armature on each side of said winding, anda yoke of insulating material mounted on the top of said core andproviding legs extending downwardly on each side of said winding toprovide stops against which said armature contacts rest when saidwinding is deenergized, said yoke providing a curved surface along whichit is ad-' justable on said core to determine the position or saidstops, with the center of curvature of said surface locatedsubstantially atthe pivotal axis of said armature.

4. A device of the class described, comprising in combination a U-shapedmagnetic core having a winding carried by one leg thereof and anarmature pivotally mounted at the end of the other core leg, contactsextending upwardly from said armature on each side of said winding, anda yoke of insulating material mounted on the top of said core andproviding legs extending downwardly on each side of said winding toprovide stops against which said armature contacts rest when saidwinding is deenergized, a block mounted on the top of said core andproviding a surface curved about the pivotal axis of said armature, witha correspondingly curved surface provided by said yoke in engagementwith said block surface, and means for holding said yokev and saidblocktogether with said surfaces in different relative positions, tosimultaneously vary the positions of both yoke stops, and therebydetermine the length said armature and core.

5. A back contact relay, comprising in combination a core membercarrying an energizing winding, an armature pivotally mounted on saidcore member and carrying spaced contacts at its free end, a yoke ofinsulating material mounted on said core member and providing spacedcontacts with which said armature contacts are in engagement when saidwinding is deenergized, said yoke providing a curved surface along whichit is adjustable to'vary the position of said yoke of the air gapbetween

